Custom_Image_Header::__construct( callable $admin_header_callback, callable $admin_image_div_callback = '' )

	public function __construct($admin_header_callback, $admin_image_div_callback = '') {
		$this->admin_header_callback = $admin_header_callback;
		$this->admin_image_div_callback = $admin_image_div_callback;

		add_action( 'admin_menu', array( $this, 'init' ) );

		add_action( 'customize_save_after',         array( $this, 'customize_set_last_used' ) );
		add_action( 'wp_ajax_custom-header-crop',   array( $this, 'ajax_header_crop'        ) );
		add_action( 'wp_ajax_custom-header-add',    array( $this, 'ajax_header_add'         ) );
		add_action( 'wp_ajax_custom-header-remove', array( $this, 'ajax_header_remove'      ) );
	}